//
// Created by Asus on 2025/6/2.
//

#include <iostream>
#include <string>
#include <bits/ostream.tcc>
using namespace std;

void demo01() {
    string str = "hello";
    str.insert(0, "123");
    cout << "str: " << str << endl;
    str.erase(0, 3);
    cout << "str: " << str << endl;
}

int main(int argc, char *argv[]) {
    demo01();
    return 0;
}
